On Kobo e-Reader: Do you need KOReader or is Kobo original UI enough?

I am a heavy user of KOReader, I have installed it on all my e-Readers that can run KOReader. On my Kindle’s, Kobo e-Readers and also on all my Android based e-Readers. Even on my Android tablets. But when it comes to Kobo e-Readers like the Kobo Libra or Kobo Clara, do you really need KOReader or isn’t the original Kobo UI enough?

Watch video here: